Measurement of functional fibrinogen levels using the Thrombelastograph

Study Objective: To validate a Thromboelastograph (Haemoscope Corporation, Niles, IL) assay for functional fibrinogen. Design: Correlation study of the Thromboelastograph assay with two conventional fibrinogen assays by the standard Clauss method. Setting: Research laboratory of a university medical center. Participants and Interventions: Blood samples were obtained from 19 healthy volunteers. Measurement and Main Results: Thromboelastograph assays, using heparinized whole blood from 19 healthy donors, indicated that reptilase-XIIIa mixture (Activator(f))-generated clot shear elasticity in dynes per square centimeter (G(f)) correlated with fibrinogen (mg/dL). Blood from four donors was used to define the contribution of hematocrit (Het) to G(f) by titration with platelet-rich plasma. The G(f) versus Hct gave linear correlations (r(2) = 0.746) with G(f) = 1258 - 17.8 x % Hct. A commercial collection of 19 normal, 10 borderline, and one deficient for functional fibrinogen-citrated plasmas was assayed for G(f) after recalcification using Activator(f). Of the 30 plasma samples, four were from factor X- or factor VII-deficient donors and one was from a coumadin-treated donor. There was a linear correlation of Activatorf Gf with functional fibrinogen (r(2) = 0.940) with G(f) = -730 + 9.21 x fibrinogen (mg/dL). Conclusion: Thrombelastography with Activatorf may be used to determine fibrinogen levels in whole blood. (c) 2008 Elsevier Inc. All rights reserved.